xvii 46.3 HVAC Alternatives for Energy Conservation .......................1237 46.4 The Role of the HVACR Technician ......1241 Section 13 Commercial Refrigeration Systems Chapter 47 Overview of Commercial Refrigeration Systems ......1244 47.1 Applications ..........................................1245 47.2 Commercial Refrigeration Systems ......1249 47.3 Industrial Applications ...........................1267 Chapter 48 Special Refrigeration Systems and Applications ......1274 48.1 Transportation Refrigeration .................1275 48.2 Alternative Refrigeration Methods ........1282 Chapter 49 Commercial Refrigeration System Confi gurations ....1294 49.1 Commercial Systems Configuration Overview ........................1295 49.2 Multiple-Evaporator Systems ................1296 49.3 Modulating Refrigeration Systems ........1298 49.4 Multistage Systems ...............................1300 49.5 Secondary Loop Refrigeration Systems ................................................1305 Section 14 Designing Commercial Refrigeration Systems Chapter 50 Understanding Heat Loads and System Thermodynamics ...............................1310 50.1 Heat Loads ........................................... 1311 50.2 Thermodynamics of the Basic Refrigeration Cycle .....................1331 Chapter 51 Commercial Refrigeration Component Selection .....1340 51.1 Sizing Compressors, Condensers, and Evaporators....................................1341 51.2 Calculating Theoretical Compressor Volume .............................1347 51.3 Designing Piping ...................................1349 Section 15 Installing and Servicing Commercial Refrigeration Systems Chapter 52 Installing Commercial Systems .............................1360 52.1 Types of Commercial Installations ........1361 52.2 Codes and Standards ...........................1362 52.3 Installing Condensing Units ..................1363 52.4 Installing Expansion Valves ..................1365 52.5 Installing Evaporators ...........................1366 52.6 Installing Refrigerant Lines ...................1368 52.7 Installing Electric Motors .......................1372 52.8 Testing Installations ..............................1375 52.9 Charging Commercial Systems ............1376 52.10 Starting a Commercial Refrigeration System ............................1380 Chapter 53 Troubleshooting Commercial Systems—System Diagnosis ................................1384 53.1 Commercial Refrigeration Troubleshooting ....................................1385 53.2 Checking Refrigerant Charge ...............1391 53.3 Diagnosing Common Symptoms ..........1392 53.4 Troubleshooting Ice Machines .............. 1415 Chapter 54 Troubleshooting Commercial Systems—Component Diagnosis ..........................1428 54.1 General Inspection Overview ...............1429 54.2 Checking Electrical Circuits ..................1430 54.3 Checking External Motors ....................1431 54.4 Checking Condensing Units .................1432 54.5 Checking Liquid Lines ..........................1445 54.6 Checking Thermostatic Expansion Valves (TXVs) .......................................1446 54.7 Checking Electronic Expansion Valves (EEVs) .......................................1447 54.8 Checking Evaporator Pressure Regulators (EPRs) ................................1448 54.9 Checking Hot-Gas Valves .....................1450 54.10 Checking Solenoid Valves ....................1450 54.11 Checking Evaporators ..........................1450 54.12 Checking Suction Lines ........................1451